But next door neighbour Emily Bishop (Eileen Derbyshire) had stumbled upon the truth. A long-time friend of Deirdre and godmother to her daughter, Tracy, Emily, strong Christian as she was, could not condone Mrs Barlow's behaviour. What would she do with the knowledge of Deirdre's deceit?
The story line covered a straight forward case of adultery but had the nation on the edge of its seats back in 1983. And yet nobody was blown up, or murdered, or raped. Modern soap watchers would probably switch off if the idea (a simple slice of human frailty with the naughty bits taken out) was repeated in a modern day soap.
From the Sunday Mirror, January 30, 1983:
Bored Deirdre Barlow's "Coronation Street" romance with smooth-talking Mike Baldwin will earn her a right talking-to tomorrow night.
Millions of enthralled fans will see the prim and proper Emily Bishop wade in to try to keep Deirdre and her plodding husband Ken together.
Viewers were left on tenterhooks last week when Emily overheard Deirdre - played by actress Anne Kirkbride - break a clandestine dinner date with factory boss Mike Baldwin.
The "Sunday Mirror" can reveal that, despite Emily's showdown with Deirdre, the Street's hottest affair will go on.
The show's producer Bill Podmore confirmed that tomorrow night's episode will see Emily, played by Eileen Derbyshire, trying to mend the Barlows' bogged-down marriage.
Bill said: "The affair continues although it does make Deirdre think about what she's doing."
The romance has been the talk of streets up and down the country.
Even the love lives of the show's regular sexpots, Elsie Tanner and barmaid Bet Lynch, have been pushed into the shade since Deirdre and Mike, played by Johnny Briggs, first kissed on screen.
Meanwhile, another Bishop warned yesterday that the affair could be a big turn-off for fans of the hit TV series.
The Bishop of Edmonton, the Right Reverend Bill Westwood said: "Too much realism killed of 'Mrs Dale's Diary' on the radio.
"The same thing could happen with 'Coronation Street' "
A spokesman for Granada TV said: "There won't be any any unpleasant scenes, no X-certificate stuff."
Sunday Mirror columnist Claire Rayner believes Deirdre should 'cool it'. If Deirdre had written to her this would have been Claire's advice: "You won't solve your boring marriage in someone else's bed. Talk to your husband about the way you feel and by communicating properly for a change."
"Someone else's bed"?!! Heavens, as far as we could see Deirdre and Mike's affair never got beyond the sofa! And nothing naughty happened at all!
Very different times on the telly.
Could Deirdre have done with an image change to re-light her marriage? On the opposite page to the featured Corrie article was the lovely vision featured above. One of the trendiest looks of 1983, apparently. Nice face, shame about the legwarmers.